how some web site block to take screen shot of web page?

Answer 1

screenshot handled by the os itself not the browser, so i dont think its possible.

Answer 2

In situations where there is DRM protection this can be handled both at hardware and software level. For example, Netflix encrypts their video so that only their own player understands it - your computer wouldn't be able to play a netflix video, their own software plays it. The software can also detect when a screenshot is being taken and switches the display to a blank screen so quickly you don't even see it.

More info: https://www.quora.com/What-technology-does-Netflix-and-other-streaming-services-use-to-prevent-someone-from-screen-capturing-a-movie-or-even-taking-a-screen-shot-I-am-a-Computer-Science-major-and-its-annoying-me-that-I-cant-figure-out-how-it-works

Answer 3

in netflix case i think its a case of software/app so its possible to capture some event in lets say an os level.

but the OP ask for the website the only thing i can think of is to bind the screenshot key to an event that immediately show blank page. but it still has so many holes.
or is it really possible to detect those event from the web page itself ?

Answer 4

I'm not an expert but I think its generally that simple - for example, on an iphone/ipad the screenshot action is a specific combination of buttons, all a website would have to do is write a function that says 'when these buttons are clicked, hide everything', similar to onClick functions for buttons.

And I think some of it is hardware level, e.g. preventing the copying of DRM-protected content.